Baden-Baden is a nice day stop. I did the same drive last November and we instead visited the champagne region. We didn't stay anywhere spectacular but found Reims to be a nice city and enjoyed the vineyards and country roads outside of town.

Colmar is a wonderful town with lovely canals and would make a good stop. There is great food and sights in riquewihr and rebauville (2 towns near Colmar, I may have butchered their names). If with foodies, French country cooking must be experienced. The expensive Auberge de I'lll is one of the greatest meals, 3-star Michellin. http://www.viamichelin.co.uk/web/Res...poi=3838_41102

If you're into history, the trenches in Verdun could be a good lesson or the kids (it is the 100th anniversary of the beginning of the First World War). If i recall correctly, St. Mihiel is about 20 minutes from the highway and it was an American offensive largelyforgotten by all but most avid history fans.